Found in a Popular Electronics from the 90s, this circuit applies to flashes with xenon lamps. The transistor admits equivalent and the phototransistor is of the Darlington type.
This 1987 signal injector included the power supply from the power grid. The transformer is 6 + 6...
This amplifier was found in a 70s documentation. The product gain x bandwidth is 350 MHz. The...
This simple receiver with junction FET uses a high impedance magnetic earphone (over 2 k). Power...